On the potential effects of sea level rise on salinity in Top End rivers

Valentine, Eric M. and Tan, Pei-Lleui (2009). On the potential effects of sea level rise on salinity in Top End rivers. In: 32nd Hydrology and Water Resources Symposium, Newcastle, 30 November - 3 December 2009.

A rise in sea level is likely to be the most challenging aspect of climate change for the low lying catchments of the coastal Northern Territory. The rivers are subject to large tidal ranges, have long tidal reaches of up to 150km and are experiencing a rate of sea level rise of 6mm per annum. This paper describes some results from a physically-based numerical model of a characteristic estuary and floodplain. The model simulates changes in salinity and morphology for various sea level scenarios and the typical extreme dry and wet season fresh water flows. Specifically, changes in saline intrusion and sediment transport and their relation to changes in the tidal limit are studied. By understanding particularly how rates of change will affect the lower reaches of these rivers, adaptation strategies may be devised which are sympathetic to the ecology and land use in these unique systems.